### What
Change from processing the file with `next-metatdata-route-loader`
directly into passing the file as loader query, and leave an empty
resource file for it. This will resolve the error that users were seeing
with `manifest.json` convention.
```
Import trace for requested module:
../../../../packages/next/dist/build/webpack/loaders/next-metadata-route-loader.js?page=%2Fmanifest.jso
n%2Froute&isDynamic=0!./app/manifest.json?__next_metadata_route__
getStaticAssetRouteCode page /manifest.json/route this.resourcePath /Users/huozhi/workspace/next.js/tes
t/e2e/app-dir/metadata-json-manifest/app/manifest.json
```
### Why
I looked at the loader process that the final resource processed by
webpack is `json!next-metadata-route-loader...`, which means the builtin
json loader processing json file after the metadata route loader. I
didn't get chance to solve the ordering issue, so I changed the
resourcePath to empty "", and pass the file path as query into the
loader to avoid json-loader processing it after transpilation.
Fixes#59923
Closes NEXT-2630
Closes NEXT-2439
